I guess it would depend on what type of music and your own personal relations to it.

When I hear music, I tend to associate movement with it, so when visualizing music in a comic, I would likely to have some type of movement with it. Some examples that I could find quickly (I don't know enough webcomics to name any)
onetwothreefour

But then, it's different from person to person. There's people who associate specific notes with specific colours. For them, it would be better to vary the colour of the words depending on what note you want it to represent. Other's might find it more like a hand grabbing their ear and dragging them away.

For my opinion, I'd say that for a comic it will be the reactions and actions of the characters that convey the emotion of the music the best.

But beyond that, you could craft the world itself to bend and flow with the style, as if the world itself sways gracefully to the sweet tones..._________________My webcomic: Mischief in Maytia
http://maytiacomic.com/